Pressure tracings Flashcards
Anacrotic notch
associated w turbulent flow during ejection
o May be apparent in systolic pressure rise
o Indicate abnormality in AoV or proximal Ao
Normal Ao peak systolic P
90-140mmHg
Dicrotic notch
associated w semilunar valve closure
o Present in systolic pressure decline
Normal Ao diastolic P
60-90mmHg
Normal ventricular pressures
- Systolic pressure correspond to associated artery
- Diastolic pressure similar to atrial pressure => close to 0
- End diastolic pressure: measured after atrial contraction (a wave), before systolic pressure rise
2 components of central AoP
- Pressure wave from forward flow (LV ejection)
- Pressure wave from reflected waves
Define reflected waves
o Generated by areas of resistance to blood flow: branch points, tortuous vessels
o Directed back to the heart
When meet AoV, generate additional smaller forward impulses
Particularly in peripheral arterial waveforms
When are reflected waves significant
CHF
AI
Systemic hypertension
incr Ao stiffness (age)
Ao or iliofemoral obstruction
Tortuosity and arterial vasoconstriction
When are reflected waves diminished
Vasodilation
Hypotension
Hypovolemia
Why peak systolic P higher vs central AoP
- Peak systolic pressure > central aortic pressure by 10-20mmHg due to peripheral amplification from reflected waves
What changes in waveform occur in peripheral arterial tree
- Further in arterial tree: pressure waveform change
o Steeper upstroke
o Narrow systolic portion
o Late, decr or absent dicrotic notch
Normal RA waveform
- 3 positive waves
o a wave: atrial contraction
Follow P wave on ECG (after 80ms)
o c wave: closed valve bulge into atrium during IVCT
During downslope of a wave
o v wave: late systole
Atrial filling gradually incr pressure
Closed AV valve
Peak at end of systole => maximal filling - End of T wave
- 2 downslopes: x and y descent
o x descent: atrial relaxation => decr pressure + lower annulus
o y descent: emptying of atrium after AV valve open
LA vs RA waveform
LA: incr mean pressure, dominant v wave
RA : dominant a wave
Normal RAP and variation
2-6mmHg
- With inspiration: mean RAP decr due to decr intrathoracic pressures
o incr passive RV filling
o More prominent y descent
RAP changes PS
- Pressure gradient across the PV => incr RV systolic pressure
o RVH => decr RV compliance => incr end diastolic RV pressure
o incr RA pressure - incr a wave => need to incr RA pressure to compensate incr RV pressure
o TS, Rv failure, PH, PS
RAP changes w TR
- Volume overload of RV and RA
o Dilation of RV => incr TR
o incr RA pressure
o decr CO - Changes in RA waveform
o Attenuated x descent
o c-v wave: systolic wave with peak dome contour
o v wave prominent
o Rapid y descent => incr volume
o incrmid to late systolic v wave
RAP changes AVB
- c wave: follow a wave during
P-R interval - 1st degree AVB => incr c wave
- Cannon a wave: atrial contraction against closed valves
RAP changes constrictive pericarditis
M or W pattern
o v wave > a wave => non-compliant RA
o Rapid y descent
Rapid atrial emptying in early diastole
incr RA pressure
Underfilled RV
o Absence of respiratory variation
Pathophys of constrictive pericarditis
o Rigid shell encasing the heart
Limit total volume of blood that enter cardiac chambers => decr ventricular diastolic filling
Early diastole: rapid filling
* > rapid vs normal because of underfilled state of RV
Mid diastole: abrupt stop => rapid incr pressure
o Ventricular interdependence
Volume/pressure of one chamber affect/is reflected in the other
o Dissociation of intrapleural/intracardiac pressures
Inspiration: decr intrathoracic pressures but not intracardiac
* incr venous return into thorax but not heart
* decr pulmonary venous pressures
o decr LV filling + decr LV pressure/preload => decr SV
o incr RV filling + incr RV pressure
Expiration = opposite
* incr intrapleural and pulmonary venous pressure
* incr PVs pressure => incr LV filling
Discordance of RV and LV systolic pressures in inspiration: spe/sens for constrictive pericarditis
* vs RCM => equal decline in LV and RV systolic pressures w inspiration
RV changes constrictive pericarditis
o Dip and plateau pattern = SQUARE ROOT SIGN
RAP changes cardiac tamponade
o Absence of y descent => rapid ventricular filling
o Equally elevated a and v waves
o Undulating flat line: elevated equalized right sided pressures
o Kussmaul’s sign:
incr RA pressure during inspiration
incr RA waveform w xY or xy pattern
RAP changes Afib
- Absence of a wave
- x descent may be present because of annulus downward motion
